The Sia euglobulin precipitation test revisited.

and reduces assay time and cost. It may also enhance the assessment of methionine loading as a tool for the investigation of hyperhomo-cystinemia and the potential role of methionine as an antioxidant [14 ]. It offers a rapid and simple alternative to the separate assay of methionine by conventional amino acid chromatography or tandem mass spectrom-etry [15 ] and is an attractive alternative to the simultaneous assay of homocysteine and methionine by GC-MS [16 ]. Matrix elimination in ion chromatography by " heart-cut " column-switching techniques .berg P. Pulsed amperometric detection of carbohydrates , amines, and sulfur species in ion chromatography—the current state of research. Measurement of total plasma cysteamine using high-performance liquid chromatography with electrochemical detection. Plasma concentrations of homocysteine and other aminothiol compounds are related to food intake in healthy human subjects. Rapid diagnosis of homocystinuria and other hypermethionine-mias from newborns' blood spots by tandem mass spectrometry. Quantitation of total homocysteine, total cys-teine, and methionine in normal serum and urine using capillary gas chromatography– mass spectrometry. To the Editor: The Sia test (Sia euglobulin precipitation test) was first described more than three-quarters of a century ago for evaluation of the euglobulin fraction in certain infectious diseases [1]. In this test, serum is diluted with water so that the ionic strength of the serum is decreased, resulting in the precipitation of euglobulins and macroglobulin [2]. Later, positivity of the Sia test was demonstrated in conjunction with clonal gammopa-thies [3– 6]. A more high-tech version of this simple test has been encountered with use of the Paramax™ chemistry analyzers [7]. When we tested a sample on our Dade Paramax 720 ZX analyzer and obtained hemolysis/lipemia warnings on all tests, even though the plasma was not visibly hemolytic/ lipemic, we become suspicious of a protein dyscrasia. We mimicked the dilution of the sample blank cuvette by adding 2.0 mL of H 2 O to 50 ␮L of serum [2]. When the mixture was visibly cloudy, cases were referred for serum protein electrophoresis. Four cases of monoclonal gam-mopathy detected by this technique were described in a Paramax technical bulletin [7]. Over ϳ2 years, a total of 61 cases of this kind have been observed in our laboratory. Of these, 41 revealed monoclonal or biclonal gammopathies; the other 20 were polyclonal. Thirty-three of these clonal proteins were further characterized by immunoelectrophoresis (18 IgM kappa, 5 IgM lambda, 8 IgG kappa, and 2 IgG …